ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character string format that combines a timestamp with random data to create identifiers that are both unique and sortable by creation time. ULIDs are an alternative to UUIDs with better sorting capabilities.

Why use ULIDs instead of UUIDs?

ULIDs offer several advantages over UUIDs: they are lexicographically sortable by generation time, they use a more compact representation (26 characters vs 36 for UUIDs), they're case-insensitive, and they avoid problematic characters like hyphens.

How do I convert a UUID to a ULID?

You can convert a UUID to a ULID using our UUID Converter tool. Simply paste your UUID into the input field and click Convert. The tool supports UUID v1, v4, v7, and any hex string, converting them losslessly to ULID format and back.

Can I decode a ULID to see its timestamp?

Yes, you can decode a ULID using our ULID Decoder tool. It will show you the timestamp in various formats (Unix timestamp, ISO string, human-readable date) and the random component in different representations.

Are ULIDs suitable for database primary keys?

Yes, ULIDs are excellent for database primary keys. They're sortable by creation time which improves database performance, they're URL-safe, and they can be generated without a central coordinator, making them ideal for distributed systems.

What is NanoID and when should I use it?

NanoID is a tiny, secure, URL-friendly unique string ID generator. It's smaller and faster than UUID and is ideal for generating short unique IDs for URLs, session tokens, or any situation where a compact random identifier is needed. Unlike ULID, NanoID is not time-sortable.

What is a Snowflake ID?

Snowflake ID is a 64-bit unique identifier format originally developed by Twitter. It encodes a timestamp, datacenter ID, machine ID, and sequence number. Snowflake IDs are sortable by time, extremely fast to generate, and widely used in distributed systems like Twitter, Discord, and Instagram.

How do I decode a JWT token?

Paste your JWT token into our JWT Decoder tool to instantly see the decoded header, payload, and signature. The tool shows all claims including expiry time (exp), issued-at (iat), and custom claims. No data is sent to any server - decoding is done entirely in your browser.

What is CUID and CUID2?

CUID (Collision-resistant Unique Identifier) is designed for horizontal scalability and sequential IDs for databases and distributed systems. CUID2 is the improved next generation with better security and randomness properties. Both are excellent alternatives to UUID for Node.js applications.

ULID Generator

Generate Universally Unique Lexicographically Sortable Identifiers with high performance

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Snowflake ID Generator

Generate highly-performant, 64-bit distributed unique identifiers (Snowflake IDs). Originally developed by Twitter, Snowflake IDs are sortable by time and fit in a standard 64-bit unsigned integer.

Snowflake ID Generator & Anatomy Visualizer

Generate, parse, and visualize distributed 64-bit Snowflake IDs

Snowflake Configuration

Epoch Preset

Datacenter ID (0 - 31) 0

Worker / Machine ID (0 - 31) 0

Sequence Number (0 - 4095) 0

Custom Timestamp / Time

Use Custom Timestamp Value

Snowflake Parser / Decoder

Parse Snowflake ID

Bit-Level Structural Anatomy (64 bits)

Hover over the sections below to see how Snowflake IDs compress dynamic temporal, machine, and sequential bits into a singular positive 64-bit integer.

Sign Bit (1 bit)

Timestamp (41 bits)

2026-05-29 17:06:06.000 UTC ms since epoch: 0

Datacenter (5 bits)

Worker / Machine (5 bits)

Sequence (12 bits)

Snowflake ID vs UUID vs ULID

Feature	Snowflake ID	ULID	UUID v4
Data Type	Yes 64-bit Integer (BigInt)	Yes 128-bit String	Yes 128-bit String (Hex)
Time-Sortable	Yes (Millisecond precision)	Yes (Millisecond precision)	No
Distributed safe	Yes (Requires Machine ID)	Yes (Randomness component)	Yes (Cryptographic entropy)
Length / Representation	Yes 19-character digit string	Yes 26 Crockford Base32 chars	No 36 hex-formatted chars
Ideal Database indexing	Yes Extremely High (Native Integer)	Yes High (String type)	No Moderate (Hex String)

Anatomy of a Snowflake ID

A standard Snowflake ID is represented as a 64-bit integer, and its bits are allocated as follows:

Sign bit (1 bit): Always 0 to ensure the generated number is positive.
Timestamp (41 bits): Millisecond epoch precision, providing up to 69 years of unique timestamps based on a custom Epoch.
Machine/Node ID (10 bits): Identifies the server instance generating the ID, supporting up to 1024 unique instances.
Sequence (12 bits): Local counter incremented within the same millisecond to prevent collisions, supporting up to 4096 unique IDs per millisecond per machine.

Ideal Use Cases

High-volume relational database primary keys (MySQL, PostgreSQL) where integer indexes are faster than strings.
Distributed logging or analytics systems that require time-sortable event indexing.
Large microservice environments where individual nodes generate unique IDs without centralized coordination.

Related tools: ULID Generator UUID Converter CUID Generator

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